Yet another 30+ year old crisp packet - just washed up on the sea's edge as I walked by. I have now found at least a dozen packs from this era (though most are not possible to date exactly as only one or two have offer end dates like this one). I am mystified as to where they are coming from as there is very little sign of degradation or colonisation of the packaging film which you would normally see if the packaging had spent a long time in the water.
My theory is that perhaps a container lost in the 1970s may have only recently shed its contents. However, this theory is slightly undermined by the fact that dates on the the packs vary by 2 years - this is longer than the shelf-life of a packet of crisps even in the 1970s when quality standards were less rigorous. Maybe landfill erosion?
If anyone has any ideas or finds any other crisp and snack packaging from the 1970s, please do e-mail me and let me know about it!